Dysphagia Lusoria

Clinical History

A middle aged lady presented with 2 years history of progressive dysphagia to solids. Her physical examination was unremarkable except evidence of recent weight loss. All routine laboratory investigations, chest x-ray and ECG were normal. Her endoscopy did not reveal anything. Contrast enhanced CT chest revealed an unusual finding.

Imaging Findings

The upper oesophagus is dilated and fluid. There is an aberrant right subclavian artery passing behind the oesophagus which could be contributing to the apparent dilatation. No mediastinal or hilar lymphadenopathy. The heart is enlarged. There isatelectasis in both lower and the right middle lobes and smooth fatty pleural thickening at the left lung base.

Discussion

Among different congenital anomalies of aortic arch, aberrant right subclavian artery is considered most common and occurs in 0.5% to 1.8% of cases [1].
The anomaly can be explained on Edward’s hypothesis which describes involution of fourth vascular arch with the right dorsal aorta. The seventh intersegmental artery remains attached to the descending aorta and this persisting intersegmental artery becomes the right subclavian artery. Differential growth shifts the origin cranially and it lies close to the origin of the left subclavian artery. It originates dorsally and therefore has a retro-oesophageal course [2].
Although most cases of this anomaly are asymptomatic, but symptoms may appear when a ring completely encircles the trachea or oesophagus. Extrinsic compression of oesophagus may lead to dysphagia. This phenomenon was first described in 1794 by a London physician David Bayford as a post-mortem finding in a woman who had lifelong dysphagia and eventually died of starvation. He named it “Dysphagia Lusoria” which means dysphagia by freak of nature [3].
Klink Hamer [4] observed that in symptomatic cases aberrant right subclavian artery was associated with a bicarotid trunk (common origin of right and left carotid arteries).
The diagnosis of Dysphagia Lusoria is difficult as the symptoms are nonspecific. Endoscopy may miss the diagnosis in 50% of cases although a pulsating mass may be visualized. Barium swallow may demonstrate a diagonal impression at the level of T3-T4. Digital subtraction angiogram, contrast enhanced CT or MRI of thorax is perhaps the best diagnostic test that could pick up the abnormality. Angiogram is needed for pre-operative assessment [5].
Management Of dysphagia lusoria depends on the severity of the condition and it ranges from dietary adjustments only to surgical resection [6].
First successful repair was reported by Robert Gross [7]. Initial reports revealed that simple division without blood flow restoration can cause ischemia of the arm. Bailey et al. in 1965 [8] attached distal end of divided vessel to ascending aorta. Cooley anastomosed distal end to right common carotid [9] This method was favoured by others but there is a possibility of cerebral ischemia with this approach. Mok et al. [10] recommended to anastomose the end to aortic arch with or without a graft. Since then numerous alternatives have been described. Some recommend an endovascular or hybrid approach to this anomaly. Endoluminal grafts have also been reported especially in presence of aneurysm [11].
Our patient was managed conservatively with dietary readjustments and showed improvement with significant weight gain in 6 months.

Differential Diagnosis List

Final Diagnosis

Dysphagia Lusoria due to aberrant right subclavian artery

URL:	https://www.eurorad.org/case/12979
DOI:	10.1594/EURORAD/CASE.12979
ISSN:	1563-4086